Neutrophilia independently predicts death in tuberculosis: Table 1–

Abstract

To the Editor: Experimental animal work indicates that neutrophils play a key role in the immune response to mycobacteria [1, 2]. They appear protective against early infection [3] but in established disease, neutrophilia associates with pathology [1, 4]. In humans, higher neutrophil counts at tuberculosis diagnosis predict slower sputum conversion to negative during therapy [5, 6], but the overall prognostic significance of neutrophilia in human tuberculosis remains elusive. We therefore aimed to analyse this phenomenon in a study powered to detect an independent relationship with mortality. Tuberculosis patients were identified by database/case-note review at Newham University Hospital Trust and King’s College Hospital, London, UK. All patients diagnosed between 1999 and 2006 were eligible for inclusion in an analysis of neutrophilia at baseline; those with a recorded outcome of successfully completing treatment or death were included in an analysis of determinants of mortality. Healthy contacts of tuberculosis cases were recruited from the same hospitals. Data were extracted on patient age, sex, ethnicity, comorbidity, use of immunosuppressive medication, HIV status and site of disease. Laboratory data were collected from samples taken on the date of tuberculosis diagnosis: serum sodium, bilirubin and albumin concentrations; peripheral blood haemoglobin concentration; and peripheral blood neutrophil, monocyte, lymphocyte and platelet counts. Blood culture results were recorded where performed. Protocols were approved by the Barking and Havering NHS Research Ethics Committee (REC 08/H0702/25) and North East London Research Ethics Committee (REC P/02/146). We calculated that 584 patients (34 deaths and 550 survivors) would be required to detect a three-fold difference in mortality in the presence of neutrophilia with 80% power (5% significance level), assuming a 15% prevalence of neutrophilia and a death/survival …